﻿<topic>
	<head>
		<title>Assert</title>
		<keywords>
			<keyword term="execution plan, assert"/>
			<keyword term="physical operators, assert"/>
		</keywords>
		<links>
			<link href="Execution Plan Reference.html">Execution Plan Reference</link>
		</links>
	</head>
	<body>
		<summary>
			<p>
				The <b>Assert</b> operator verifies a condition. For example, it validates that a scalar subquery returns one row. For each input row,
				the <b>Assert</b> operator evaluates the expression in the <c>Predicate</c> property. If this expression evaluates to <c>NULL</c>, the
				row is passed through the <b>Assert</b> operator. If this expression evaluates to a non-<c>NULL</c> value, the appropriate error will
				be raised.
			</p>

			<p>
				The <b>Assert</b> operator is a physical operator.
			</p>
		</summary>

		<section title="Properties">
			<table>
				<tr>
					<th>Property Name</th>
					<th>Description</th>
				</tr>
				<tr>
					<td>Predicate</td>
					<td>
						Specifies the condition that must evaluate to <c>NULL</c>.
					</td>
				</tr>
			</table>
		</section>
	</body>
</topic>
